Blower for steam-boiler furnaces.



E; B. PITTS, Sn. BLOWER FOR STEAM BOILER FURNACES.

APPLICATION FILED MAY 22, 1,915-

Patented May 8, 1917.

2 SHEETS-SHEET I E. B. PITTS, SR.

BLOWER FOR STEAM BOILER FURNACES.

APPLICATION FILED MAY 22. I915.

2 SHEETS-SHEET 2.

1,25,3953 Patefited May 8, 1917.

as snares Parana oration EDWIN IB. PITTS, SR., 015 OSWEGO, NEW YORK.

BLOWER FOR STEAM-BOILER FURNACES.

Specification of Letters Patent.

Applicatibn filed. May 22, 1915. Serial No. 29,749.

1/ '0 all whom it may concern:

Be it known that I, EDWIN B. Prr'rs, Sn, a citizen of the United States, residing at ()swego, in the county of Oswego and State of New York, have invented certain new and useful Improvements in Blowers for Steam-Boiler Furnaces, of which the following is a specification.

This invention relates to steam boiler furnaces and consists in an improved construction of apparatus for promoting combustion in such furnaces. More particularly, the invention seeks to provide improved means for utilizing the exhaust steam from an engine for producing a forced draft through the furnace, and contemplates the provision of a blower of special construction so arranged as to introduce a current of steam and air under the grate. The invention also includes an improved construction of fan blower whereby the relative proportion of steam and air may be varied as desired. V s

In order that the invention may be readily understood, reference is had to the accompanying drawings, forming part-of this specification, and in which,

Figure 1 is a conventional front view of a pair of boilers showing my invention applied thereto;

Fig. 2 is an enlarged central, longitudinal section through one of my improved blowers, parts being in elevation;

Fig. 3 is a view of the improved fan which I employ;

Fig. 4 is an end view of the special nozzle for directing steam against the fan blades; and,

Figs. 5 and 6 are fragmentary transverse sections through one of the outer and inner fan blades, respectively, parts being in .ele-C vation.

Referring to the drawings in detail, I have illustrated in Fig. 1 a pair of boilers designated in their entirety by the reference numerals A and B, and have indicated the fire-doors at 1 and the ashpit doors at 2. These boilers and furnaces may be of any usual construction. While my invention may be equally as well employed with a single boiler and furnace, I have illustrated in Fig. 1 how it may be applied to two such boilers. T j

3 designates the pipe through which the;

exhaust s eam capes from the eng ne, (n t shown) and this pipedischarges into a tank 4, which is shown as arranged above one of the boilers, but may be located in. any convenient position desired... From this tank extends a blow-ofi' pipe 5 in which is a. weight controlledvalve 6, which may be set to permit the escape of steam from the tank whenany desired pressure is reached. In practice, I have found thatsetting this valve at 5 pounds pressure to the square inch gives good results and prevents excessive back pressure on the engine. It will be understood that the low pressure steam from this tank may also be utilized for heating or other purposes. From the tank 4 extends a pipe 7 downwardly to a. point below the level of the grates under the boilers, and at its lower end is preferably provided with a three-way fitting 8, having horizontally extending branches 9 and 10. As the apparatus associated with these branches is identical for each boiler, a description. of one will suffice for both. I

Referring then to Fig. 2, it will be seen that the branch 10 projects into a tube 11, set into the wall of the furnace and preferably having an outwardly flaring mouth as shown, to facilitate the inflow of air. Spaced from the branch or nipple 1Q and extending in line therewith, concentrically of the tube 11, is an injector tube 12 ofthe same size as the nipple 10, and supported within the tube 11 by means of suitable brackets 13.

The end of the nipple 10 is closed by means of a screw cap 14, having a plurality of arc-shaped openings or slots 15 formed in the same, as clearly shown in Fig. 4. The nipple 10 and cap 14 thus constitute a nozzle for directing steam against'the fan now to be described.

The fan or blower consists of a central hub 17, fast upon a shaft 18, supported at one end in a socket 16, formed in the cap 14, and at the other end in bearings 19, supported by a spider or bracket 20. From the hu.b 1 7 extend a plurality of radially d1sposed blades 21, secured at their outer ends to a ring 22. This ring is of the same d 1- ameter as the nipple 10 and tube 12, and is of a width to snugly fit between the outer faceof the cap 14 and the end of tube 12, so that the fan blades 21 run as closely as possible to the cap 14. The blades 21, as shown in. F g- 6, are prefera ly set at quite an acute angle to the axis of the fan so as to impede the flow of steam therethrough to' as small an extent as possible.

Extending radially outward from the ring 22 is a second series .of fan blades 23, se-

cured at their outer ends to a second ring 24,

which is of such a diameter as to just clear th inside of the tube 11.-

From the foregoing it will be seen that steam issuing from the nozzle openings impinges against the blades 21, and thus causes the fan blower to revolve at a high rate of speed. The blades 21 and nozzle, in

fact, constitute a steam turbine of the impact, axial flow type. The steam after leavmg. the blades 21 passes on through the tube 12, and as it issues from the inner end thereof, produces an injector action which tends to draw air in through the tube 11. In addition, the fan blades 23 act to draw in and impel air through the-tube 11 which passes on and mingles. with the steam. It

will be noted that the thrust of the steam against the blades 21 tends to urge the fan device toward the right, while the reaction of the fan blades 23 on the air being driven tends to urge the fan device to the left.

Thus, the action of the steam and air on the blades 21 and 23 is substantially balanced so that there is very little thrust on the shaft 18. v

The blades 23 of the blower are preferably set at a greater angle to the axis of the fan shown in Fig. 5. The blades themselves are centrally pivoted at each end in the rings 22 and 24, on p vots 25, so that they may be turned by shlfting the ring 26. This ring may be clamped. in adjusted position by means of bolts 28, passing through the ring and through circumferential slots in the ring 22. It will be apparent that by changing the angle or pitch of the blades 23, the amount of air propelled thereby can be varied as deslred, and therefore, the relative proportions of steam and air admitted to the furnace governed accordingly.

By means of the above apparatus I am enabled to utilize the exhaust steam which would, otherwise be wasted, and thus efi'ect.

great economy 'in the operation of the furnaces. J

WhatI claim is: 1. In a device of the character described, the combination with an intake tube of a steam nozzle mounted centrally therein and a combined steam turbine and fan mounted in said tube with the turbine adjacent said nozzle so as to be driven by steam issuing .take tube and disposed in axial alinement with said nozzle, a steam turbine mounted between said nozzle and injector tube and being of substantially the same diameter as said tube so that steam issuing from said nozzle passes through said turbine and thence through said injector tube, and a fan blower surrounding said turbine whereby air is forced through said intake tube by the combined effect of said fan and the injector action of the steam jet.

3. A blower device for steam boiler furnaces comprising an intake tube, a steam nozzle centrally disposed therein and extending axially thereof, said nozzle being closed by a cap provided with a plurality of slots, a turbine mounted adjacent said slots so as to receive the impact of steam issuing therefrom, and a fan surrounding said turbine and rigidly secured thereto, said fan serving to impel air through the annular space between said tube and nozzle.

In testimony whereof I have aflixed my signature;

' EDWIN B. PITTS, Sn. 

